program main

!*****************************************************************************80
!
!! machine_test() tests machine().
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    24 April 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  call timestamp ( )
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'MACHINE_TEST():'
  write ( *, '(a)' ) '  FORTRAN90 version'
  write ( *, '(a)' ) '  Test MACHINE().'

  call d1mach_test ( )
  call i1mach_test ( )
  call r1mach_test ( )
!
!  Terminate.
!
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'MACHINE_TEST:'
  write ( *, '(a)' ) '  Normal end of execution.'
  write ( *, '(a)' ) ' '
  call timestamp ( )

  stop 0
end
subroutine d1mach_test ( )

!*****************************************************************************80
!
!! D1MACH_TEST reports the constants returned by D1MACH.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    29 March 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0D+00 )

  real ( kind = rk ) d1mach

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'D1MACH_TEST'
  write ( *, '(a)' ) '  D1MACH reports the value of constants associated'
  write ( *, '(a)' ) '  with real double precision computer arithmetic.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Assume that double precision numbers are stored '
  write ( *, '(a)' ) '  with a mantissa of T digits in base B, with an '
  write ( *, '(a)' ) '  exponent whose value must lie between EMIN and EMAX.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  For input arguments of 1 <= I <= 5,'
  write ( *, '(a)' ) '  D1MACH will return the following values:'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  D1MACH(1) = B^(EMIN-1), the smallest positive magnitude.'
  write ( *, * ) d1mach(1)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  D1MACH(2) = B^EMAX*(1-B^(-T)), the largest magnitude.'
  write ( *, * ) d1mach(2)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  D1MACH(3) = B^(-T), the smallest relative spacing.'
  write ( *, * ) d1mach(3)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  D1MACH(4) = B^(1-T), the largest relative spacing.'
  write ( *, * ) d1mach(4)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  D1MACH(5) = log10(B).'
  write ( *, * ) d1mach(5)

  return
end
subroutine i1mach_test ( )

!*****************************************************************************80
!
!! I1MACH_TEST reports the constants returned by I1MACH.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    29 March 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer i1mach

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'I1MACH_TEST'
  write ( *, '(a)' ) '  I1MACH reports the value of constants associated'
  write ( *, '(a)' ) '  with integer computer arithmetic.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with input/output units:'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(1) = the standard input unit.'
  write ( *,     * ) i1mach(1)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(2) = the standard output unit.'
  write ( *,     * ) i1mach(2)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(3) = the standard punch unit.'
  write ( *,     * ) i1mach(3)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(4) = the standard error message unit.'
  write ( *,     * ) i1mach(4)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with words:'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(5) = the number of bits per integer.'
  write ( *,     * ) i1mach(5)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(6) = the number of characters per integer.'
  write ( *,     * ) i1mach(6)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with integer values:'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Assume integers are represented in the S digit '
  write ( *, '(a)' ) '  base A form:'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Sign * (X(S-1)*A^(S-1) + ... + X(1)*A + X(0))'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  where the digits X satisfy 0 <= X(1:S-1) < A.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(7) = A, the base.'
  write ( *,     * ) i1mach(7)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(8) = S, the number of base A digits.'
  write ( *,     * ) i1mach(8)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(9) = A^S-1, the largest integer.'
  write ( *,     * ) i1mach(9)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with floating point values:'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Assume floating point numbers are represented '
  write ( *, '(a)' ) '  in the T digit base B form:'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    Sign * (B^E) * ((X(1)/B) + ... + (X(T)/B^T) )'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  where '
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '    0 <= X(1:T) < B,'
  write ( *, '(a)' ) '    0 < X(1) (unless the value being represented is 0),'
  write ( *, '(a)' ) '    EMIN <= E <= EMAX.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(10) = B, the base.'
  write ( *,     * ) i1mach(10)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with single precision values:'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(11) = T, the number of base B digits.'
  write ( *,     * ) i1mach(11)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(12) = EMIN, the smallest exponent E.'
  write ( *,     * ) i1mach(12)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(13) = EMAX, the largest exponent E.'
  write ( *,     * ) i1mach(13)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Numbers associated with double precision values:'
  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(14) = T, the number of base B digits.'
  write ( *,     * ) i1mach(14)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(15) = EMIN, the smallest exponent E.'
  write ( *,     * ) i1mach(15)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  I1MACH(16) = EMAX, the largest exponent E.'
  write ( *,     * ) i1mach(16)

  return
end
subroutine r1mach_test ( )

!*****************************************************************************80
!
!! R1MACH_TEST reports the constants returned by R1MACH.
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    29 March 2007
!
!  Author:
!
!    John Burkardt
!
  implicit none

  integer, parameter :: rk = kind ( 1.0E+00 )

  real ( kind = rk ) r1mach

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) 'R1MACH_TEST'
  write ( *, '(a)' ) '  R1MACH reports the value of constants associated'
  write ( *, '(a)' ) '  with real single precision computer arithmetic.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  Assume that single precision numbers are stored '
  write ( *, '(a)' ) '  with a mantissa of T digits in base B, with an '
  write ( *, '(a)' ) '  exponent whose value must lie between EMIN and EMAX.'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  For input arguments of 1 <= I <= 5,'
  write ( *, '(a)' ) '  R1MACH will return the following values:'

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  R1MACH(1) = B^(EMIN-1), the smallest positive magnitude.'
  write ( *, * ) r1mach(1)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  R1MACH(2) = B^EMAX*(1-B^(-T)), the largest magnitude.'
  write ( *, * ) r1mach(2)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  R1MACH(3) = B^(-T), the smallest relative spacing.'
  write ( *, * ) r1mach(3)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) &
    '  R1MACH(4) = B^(1-T), the largest relative spacing.'
  write ( *, * ) r1mach(4)

  write ( *, '(a)' ) ' '
  write ( *, '(a)' ) '  R1MACH(5) = log10(B).'
  write ( *, * ) r1mach(5)

  return
end
subroutine timestamp ( )

!*****************************************************************************80
!
!! timestamp() prints the current YMDHMS date as a time stamp.
!
!  Example:
!
!    31 May 2001   9:45:54.872 AM
!
!  Licensing:
!
!    This code is distributed under the MIT license. 
!
!  Modified:
!
!    06 August 2005
!
!  Author:
!
!    John Burkardt
!
  implicit none

  character ( len = 8 ) ampm
  integer d
  integer h
  integer m
  integer mm
  character ( len = 9 ), parameter, dimension(12) :: month = (/ &
    'January  ', 'February ', 'March    ', 'April    ', &
    'May      ', 'June     ', 'July     ', 'August   ', &
    'September', 'October  ', 'November ', 'December ' /)
  integer n
  integer s
  integer values(8)
  integer y

  call date_and_time ( values = values )

  y = values(1)
  m = values(2)
  d = values(3)
  h = values(5)
  n = values(6)
  s = values(7)
  mm = values(8)

  if ( h < 12 ) then
    ampm = 'AM'
  else if ( h == 12 ) then
    if ( n == 0 .and. s == 0 ) then
      ampm = 'Noon'
    else
      ampm = 'PM'
    end if
  else
    h = h - 12
    if ( h < 12 ) then
      ampm = 'PM'
    else if ( h == 12 ) then
      if ( n == 0 .and. s == 0 ) then
        ampm = 'Midnight'
      else
        ampm = 'AM'
      end if
    end if
  end if

  write ( *, '(i2,1x,a,1x,i4,2x,i2,a1,i2.2,a1,i2.2,a1,i3.3,1x,a)' ) &
    d, trim ( month(m) ), y, h, ':', n, ':', s, '.', mm, trim ( ampm )

  return
end